Vice President Joe Biden waves to the crowd as he walks down Pennsylvania Avenue en route to the White House, Monday, Jan. 21, 2013, in Washington. Thousands marched during the 57th Presidential Inauguration parade after the ceremonial swearing-in of President Barack Obama. (AP Photo/Carolyn Kaster)

WASHINGTON—Joe Biden in 2016? The inauguration is barely over but the vice president already is dropping plenty of hints that he might have another political act.

Biden packed his schedule with events and receptions attended by party stalwarts throughout the long weekend of inauguration festivities, stoking speculation he may be laying the groundwork to carry the torch from President Barack Obama. It comes after Biden played a prominent role in brokering a compromise on the fiscal cliff standoff with Congress and his work developing gun violence legislation following December's deadly school shooting in Connecticut.

The next presidential campaign is a long way off and the Democratic primary chase will be dotted with plenty of "ifs," most notably whether outgoing Secretary of State Hillary Rodham Clinton decides to seek the nomination. Clinton, the former New York senator and first lady, remains the heavy favorite among party activists but several notable Democrats, including Biden, New York Gov. Andrew Cuomo and Maryland Gov. Martin O'Malley, are said to be keeping their options open in case Clinton decides not to run again.

As vice president, Biden can stay in the spotlight and is no stranger to the demands of a presidential campaign after failed bids in 1988 and 2008. The former Delaware senator has racked up a long list of domestic and foreign policy achievements even as his occasional off-script moments have become fodder for Republicans.

"There's a whole lot of reasons why I wouldn't run," Biden, who will be nearly 74 on Election Day in 2016, told CNN in an interview before the inauguration. "I don't have to make that decision for a while. In the meantime, there's one thing I know I have to do, no matter what I do. I have to help this president move this country to the next stage."

Yet with his high-profile perch, Biden is doing nothing to tamp down the speculation.

Biden's private swearing-in ceremony on Sunday was attended by recently elected New Hampshire Gov. Maggie Hassan, someone who would be a potent ally in the state's first-in-the-nation primary. Attendees at a Sunday afternoon reception at the vice president's residence at the Naval Observatory said they noticed a lot of party activists from early voting states like New Hampshire, Iowa and South Carolina.

"We can always start the political calculations in terms of the number of delegates needed to secure a nomination. But let's just say I see a number of superdelegates here as well," Democratic strategist Donna Brazile told reporters following the ceremony.

Biden later dropped by the Iowa State Society Inaugural Ball, slipping up and telling partygoers he was "proud to be president of the United States," prompting cheers. He quickly corrected himself, saying he was "proud to be vice president of the United States, but I am prouder to be ... President Barack Obama's vice president." Laughing it off, he said, "There's goes that."

During the weekend, Biden attended a ball at the Kennedy Center celebrating the party's Latino voters, who turned into a powerful voting bloc in November's election. Biden called the Latino community "a decisive factor" in the election. "This is your moment," Biden said. "America owes you." Some party stalwarts said it was noteworthy that Biden asked Supreme Court Justice Sonia Sotomayor, the first Latina justice, to administer the oath of office.

Biden also attended a ball honoring environmentalists, sponsored by the National Wildlife Federation and other environmental groups, where he said the Obama administration was committed to confronting climate change. "I don't intend to let these four years go by without getting a hell of a lot done," on the environment, Biden said.

On Inauguration Day, Biden and his wife, Jill, walked part of the parade route, waving to the cheering crowds in a made-for-TV moment. At one point, the vice president even jogged across Pennsylvania Avenue to shake hands with "Today" show weatherman Al Roker.

"It seems obvious that he's going to keep that option open for himself and do the right things," said Mike Gronstal, the Democratic leader of the Iowa state Senate who attended the reception. Gronstal said Biden actively worked the room, thanking supporters for their help during the 2012 campaign. "It was very personal time," he said.

On Tuesday afternoon, Biden met with members of the Democratic National Committee at a private reception after a DNC meeting, where delegates unanimously re-elected Florida Rep. Debbie Wasserman Schultz to another term as chairman. A frequently played campaign theme song, REO Speedwagon's "Roll with the Changes," could be heard from outside the room and attendees said Biden thanked them for their work during the campaign and offered an upbeat assessment of the second term.

If Clinton decides not to run, Biden could draw upon good will from party activists, an ability to connect with regular folks and extensive campaigning in key states like Iowa, New Hampshire, Florida and Ohio. But he would also need to deal with personal poll numbers that rank below Obama's and a propensity to commit foot-in-mouth moments in an era where political gaffes can quickly sink a campaign.

New Hampshire state Sen. Martha Fuller Clark, who was among the attendees at Biden's Sunday reception, said it was "early to read into" Biden's interest in 2016. But he said there was "huge support" in the key primary state.

"He's deeply admired and loved in New Hampshire," Clark said. "Clearly Joe Biden occupies a key place in our hearts."